Single-Point Left Ventricular Pacing Optimized by ECG Results in Better
Resynchronization than Multipoint Pacing
Abstract
Background: Multipoint pacing (MPP) in cardiac resynchronization therapy
(CRT) activates the left ventricle from two locations, thereby
shortening the QRS duration and enabling better resynchronization;
however, compared with conventional CRT, MPP reduces battery longevity.
On the other hand, electrocardiogram-based optimization using the
fusion-optimized intervals (FOI) method achieves more significant
reverse remodeling than nominal CRT programming. Our study aimed to
determine whether MPP could attain better resynchronization than
single-point pacing (SPP) optimized by FOI. Methods: This prospective
study included 32 consecutive patients who successfully received CRT
devices with MPP capabilities. After implantation, the QRS duration was
measured during intrinsic rhythm and with three pacing configurations:
MPP, SPP-FOI, and MPP-FOI. In 14 patients, biventricular activation
times (by electrocardiographic imaging, ECGI) were obtained during
intrinsic rhythm and for each pacing configuration to validate the
findings. Device battery longevity was estimated at the 45-day
follow-up. Results: The SPP-FOI method achieved greater QRS shortening
than MPP (-56±16 vs. -42±17 ms, P<0.001). Adding MPP to the
best FOI programming did not result in further shortening (MPP-FOI: -
58±14 ms, P=0.69). Furthermore, the biventricular activation time
according to ECGI was also shorter with SPP-FOI than with MPP. The
estimated battery longevity was longer with SPP than with MPP (8.1±2.3
vs. 6.3±2.0 years, P=0.03). Conclusions: SPP optimized by FOI resulted
in better resynchronization and longer battery duration than MPP.